Single element printing machine



March 31, 1959 E E. PALMERIETAL 2,879,876

SINGLE ELEMENT PRINTING MACHINE Filed Nov. 17, 1955 17 Sheets-Sheet 1INVENTORS LEON E. PALMER RALPH E. PAGE JOHN E. H KERSON gpdu lambATTORNEY- L. E. PALMER ETAL SINGLE ELEMENT PRINTING MACHINE March 31,1959 17 Sheets-Sheet 2 Filed Nov. '17, 1955 ERSON K a) rm ATTO NEYINVENTORS LEON E. PALMER RALPH E. PAGE JOHN E March 1959 Y E. PALMER ETAL ,879,876

SINGLE ELEMENT PRINTING MACHINE Filed Nov. 17, 1955 17 Sheets-Sheet 3SHIFT MECHANISM .1 INVENTORS LEON E. PALMER RALPH E. PAGE OHN E. HIKERSON lmumo ATTORNEY March 31, 1959 Filed Nov. 17, 1955 FIG. 3A I E.PALMER ETAL I 2,879,876 S INGLE ELEMENT PRINTING MACHINE 17 Sheets-Sheet4 INVENTORS LEON E. PALMER RALPH E. PAGE JOHN E.Hl KERSON &) mum:

ATTORNEY.

March 31, 1959 E. PALMER ETAL 2,879,876

SINGLE ELEMENT PRINTING MACHINE Filed Nov. 17, 1955 17 Sheets-Sheet 5FIG. 4A

INVENTO LEON E. PAL R RALPH E.PAGE JOHN E. HICKERSON $5.05 IATLORNEYMarch 31, 1959 E. PALMER ET AL 2,879,876

SINGLE ELEMENT PRINTING MACHINE Filed Nov. 17, 1955 v I 17 Sheets-Shet 6VENTORS LE E. PALMER PH E. PAGE N E. H KERSON w biMlMlb ATTORNEY March31, 1959 Filed NOV. 17, 1955 FIG. 4C]

L. E. PALMER ETAL SINGLE ELEMENT PRINTING MACHINE 17 Sheets-Sheet '7LEON E. PALMER a) ll (M ATTORNEY March 31, 1959 Filed Nov. 17, 1955 FIG.45

' L. E. PALMER ETAL SINGLE ELEMENT PRINTING MACHINE 1'7 Sheets-Sheet 8March 31, 1959 E. PALMER ETAL ,8

7 SINGLE ELEMENT PRINTING MACHINE Filed Nov. 17, 1955 '1'!" Sheets-Sheet9 FIG. 5B

- INVENTORS LEON E. PALMER RALPH E. PAGE JOHN E. H KERSON g w numlb ATTORN EY 1.. E. PALMER ETAL SINGLE ELEMENT PRINTING MACHINE March 31,1959 17 Sheets-Sheet 10 Filed Nov. 17, 1955 zmaum M355 INVENTORS E.PALMER RALPH E. PAGE LEON JOHN E. H KERSON l'wlum TTORNEY March -31,1959 L. E. PALMER ET AL sINELE ELEMENT PRINTING MACHINE 17 Sheets-Sheet11 Filed Nov. 17, 1955 INVENTORS LEON E. PALMER RALPH E.- PAGE JOHN E.HKERSON ATTORNEY March 31, 1959 E. PALMER ETAL S INGLE ELEMENT PRINTINGMACHINE 1'7 Sheets-Sheet 12 Filed Nov. 17, 1955" INVENTORS ATTORNEY vMarch 1959 L. E. PALMER ET AL SINGLE ELEMENT PRINTING MACHINE 1'7Sheets-Sheet 13 Filed Nov. 17, 1955 March 31, 1959 L. PALMER ETAL SINGLEELEMENT PRINTINGYMACHINE 17 Sheets-Sheet .14

Filed Nov. 1'7. 1955 INVENTORS E. PALMER LEON RALPH E. PAGE Filed Nov.17, 1955 March 1959 L. E. PALMER ETAL 2379;876-

SINGLE ELEMENT ,PRINTING MACHINE 1'7 Sheets-Sheet 15 FIG. 12

INVENTORS LEON E. PALMER RALPH E. PAGE JOHN E. HICKERSQN a mm ATT RNEY'March 31-, 1959 r E. PALMER ETAL 2,379,376

S'INGLE ELEMENT PRINTING MACHINE l7 Sheets-Sheet 16 Filed Nov. 17, 1955ZOTZEMEO Qmmm ZOmmE INVENTORS E. PALMER RALPH E. PAGE ERSON OHN E March31, 1959 Filed Nov. 1'7, 1955 4L. E. PALMER ETAL 2,879,876

SINGLE ELEMENT PRINTING MACHINE l7 Sheets-Sheet 17 :FIRST CHARACTER-sEcoND CHARACTER 400 RPM DRIVE FILTER SHAFT 120.0 RPM DRIVE CAM SHAFTKEY LEVER BAIL- FILTER CLUTCH 1 REV FILTER SHAFT INTERPOSER MOTIONHORIZONTAL 1 REV CAM SHAFT SELECTOR CAMS RIBBON LIFT RIBBON FEED PRINTCAR R I E R ESCAPEMENT INVENTORS LEON E. PALMER RALPH E. PAGE OHN E.CKERSON [a mola ATTORNEY FIG. 14

United States Patent SINGLE ELEMENT PRINTING MACHINE Leon E. Palmer andRalph E. Page, Poughkeepsie, and

, John E. Hickerson, Wappingers Falls, N.Y., assignors to InternationalBusiness Machines Corporation, New York, N.Y., a corporation of New YorkApplication November 17, 1955, Serial No. 547,482

11 Claims. (Cl. 19716) This invention relates to typewriters and moreparticularly to an improved single element typewriter having an improvedselecting and printing mechanism.

By definition, a single element typewriter is one having a, singleelement printing head wherein all the characters of a type font arepositioned on the surface of one printing device, which device may bepositioned for printing engagement with a paper carrier with a selectedcharactor of the type font in printing position.

It is well known in the typewriting art that much of the noise ofconventional typewriters is a result of the print action of a low masshigh velocity type bar. Printing noise may be reduced materially throughthe use of a high mass low velocity printing head, and it is afirstobject of this invention to provide such an improved quietprintin'gmechanism.

'In earlier single element typewriters, the mass behind each characterat the instant of printing was not uniform, with the natural result thatprint density of the characters varied, and accordingly it is a furtherobject of this in vention to provide an improved single elementtypewriter wherein the mass behind each print blow is substantiallyuniform.

It is a further object of this invention to provide an improvedtypewriter wherein the paper holder is stationary while the printingelement is moved across the page whereby the machine requires lessoperating room.

It is a further object of this invention to provide a stationary paperholder typewriter whereby the printing mechanism may be enclosed toreduce the noise.

It is a further object of this invention to provide an improvedtypewriter wherein the type font is readily interchangeable.

It is a further object of this invention to provide an improved singleelement typewriter wherein the rate of print strokes is cyclicallycontrolled to provide a predetjermined minimum time between printstrokes.

7 It is a still further object of this invention to provide a singleelement typewriter having an improved case shift mechanism.

It is a further object of this invention to provide a single elementtypewriter having an improved selecting mechanism for determining thecharacter that is to be printed.

It is a still further object of this invention to provide a singleelement typewriter having an improved selecting.

mechanism which facilitates adapting the machine for re mote control.

It is a still further object of this invention to provide a typewriterhaving a character selecting mechanism wherein a uniform key lever forcetriggers a power operated selection.

Other objects of the invention willbe pointed out inthe followingdescription and claims and illustrated in the accompanying drawings,which disclose, by way of ex- Fig. l is a perspective drawing of themachine with the cover removed.

Fig. 2 is a section through plane 22 of Fig. 1.

Fig. 2B is a perspective view of a portion of a shift mechanism.

Fig. 2C is an enlarged side elevation of the shift clutch shown in Fig.2B.

Fig. 2D is a section of the shift clutch taken through plane 2D2D ofFig. 2C.

Fig. 3 is a perspective view showing a portion of a selection controlmechanism.

Fig. 3A is a section of the cycling clutch taken through plane 3A--3A ofFig. 3.

Fig. 4A is a perspective view showing the selecting cams.

Fig. 4B is a continuation of Fig. 4A including a one revolution clutchand a shift clutch.

Fig. 4C is a diagrammatic perspective view of the wires controllingrotation of a single element print head.

Fig. 4D is a diagrammatic perspective view of the wires controlling atilt operation of .the single element print head.

Fig. 4E is a code chart.

Fig. 5A is a perspective view showing the operation of the platenindexing mechanism.

Fig. 5B is a side elevation of the indexing cam and cooperating pawlstaken along plane 5B--5B of Fig. 5A.

Fig. 6 is a perspective view showing a carriage return mechanism.

Fig. 7.is a perspective view showing a back space mechanism.

Fig. 8 is a perspective view showing the space bar and esca-nernentmechanism. I

Fig. 9 is a perspective view showing the tabular mechanlsm.

Fig. 9A is an enlarged perspective view of the tab latching mechanism inan. unlatched position.

Fig. 9B is an enlarged perspective view of the tab latching mechanismina latched position.

Fig. 10 is a perspective view showing the type head and carriermounting.

Fig. 11 is a perspective view of the head carrier showing the print cam.

Fig. 12 is an exploded perspective view of the paper guide, and itssupporting frame.

Fig. 13 is an exploded perspective view showing the ribbon feedoperation. I i

Fig. 14 is a timing diagram.

Briefly, this invention relates to an improved single elementtypewriter. acting in combination with mechanisms for cyclicallyselecting and printing a predetermined character. In a P eferredembodiment, the printing element is character spaced across a page andat each printing position, a cycle of operation is instituted inresponse to manipulation of a key'lever wherein one character is platen,

first selected, and then printed.

v ing fashion. The type head 8 is supported on a carriage 10 which ismovable along guide rails 12, 14 across the paper feed unit. In thisrespect, this typewriter is unconventional in that the paper feed unitremains stationary while the printing element moves across the page. jThetypewriter is also provided with theusual key I levers 16 havingtheir own key buttons 18, respectively.

ample, the principle of the invention and the best mode,

which has been contemplated, 0f PP Y that p p 9 lever is rockedcounterclockwise within the limits defined In the drawings:

The key levers 16 (Fig. 2) are shown pivotally supported about a fulcrumrod 20 which extends transversely of the machine in a conventionalmanner. When a key by a conventional guide comb '24, it acts on aninterposer' 22 (one for each key lever, respectively). The interposersare pivotally supported about fulcrum rod 26 [which extends transverselyof the machine) in such a manner that each interposer can bothbe rockedclockwise about the fulcrum rod 26 and slid transversely within :helimits defined by the slotted opening 28.

Each key lever 16 is provided with a finger 30 which acts on a bent overear 32 extending integrally from the :Orresponding interposer 22.Actually, the finger 30 pushes on the bent over ear 32 to rock theinterposer :lockwise about the fulcrum wire 26, and in doing so, a hail34, which extends transversely of the machine, is moved downward to atripping position as well as hereinafter explained.

The bail 34 is used to trigger a clutch which will be later described tocause a one-third revolution of a filter shaft 36. It will be noted thatwhen the interposer 22 has been rocked clockwise into an active position(dotted line position of Fig. 2), an actuating shoulder 38 is positionedfor engagement by one of the lobes 40 of the filter shaft 36, which lobewill drive the interposer 22 to the left as viewed-in Fig. 2 within thelimit of the elongated slot 28. In this movement of the interposer shaftto the left, it will be noted that a plurality of selecting fingers 42which are an integral part of the interposer 22 will act to rockpredetermined selecting bails 44 about their shoulder 38 to drive theinterposer 22 to the left.

next succeeding lobe on the primary 58. More specifically, withreference again to Fig. 2, it was mentioned that the lobe 40 on thefilter shaft 36 pushes on the actuating It will be noted that theinterposer 22 is spring biased by the spring 70 upward and to the right.Accordingly, it can be appreciated that when the interposer 22 is drivento the left, and as soon as it is removed from contact with the keylever tripping finger 30, the spring 70 will take over tending to pullthe interposer counterclockwise about the fulcrum 26, which action willdisengage the interposer from the filter shaft 36 and thus release thebail 34 which in turn will restore the trip pawl 56 to the positionshown in Fig. 3. In order to insure this disengagement, a stop 71 ispositioned transversely of all the interposers to engage a camming ear73 which forces the interposer upward. Actually, the arrangement ofparts is such that after the filter shaft 36 has made oneninth of arevolution, the interposer 22 will be disengaged from the trippingfinger 30 and hence the bail 34 and the trip pawl 56 have a time equalto the remaining twoninths of a revolution of the filter shaft 36 to berestored.

It has been found in operation that the timing is such pivots '46.Actually, the selecting fingers 42 are arranged in some combination ofseven so that any number of selecting balls 44 (up to seven) may berocked about Operation of the filter shaft .Withreference to Fig. 3, a.filter belt 50 is illustrated as being driven under control of a motor,not shown, to drivev a filter pulley 52 in a counterclockwise directionas shown by the arrow in Fig. 3. It has been mentioned that the bail 34is depressed each time a key lever is rocked. Actually, as shown in Fig.3, the bail 34 is pivotally supported about an axis 53 of a crank member54 which, in turn, is supported in the side frame. The rocking of thebail about its axis 53 causes a filter pawl 56 (attached to crank member54) to be lifted out of engagement with a lobe on a primary filter cam58. (See Fig. 3A.) Actually, as shown in Fig. 3A, the pulley 52 isrotatable freely about the filter shaft 36. But pulley 52 is connectedvia a filter or spring clutch 60 to the filter shaft 36. In detail, thefilter clutch 60 comprises a primary member 58 and a secondary member64, with the secondary member being pinned or otherwise secured by a setscrew to the filter shaft 36 and with the primary and secondary membersbeing interconnected via a coil spring 66. When in the position shown inFig. 3, the coil spring will be unwound to a large diameter therebypermitting the hub of pulley 52 to rotate freely on the filter shaft 36;but when the spring clutch is tightened, it will grip the hub of pulley52 and thereby drive the filter shaft 36. In the illustration shown inFig. 3, the filter pawl 56 is in engagement with a lobe on the primary58 of the filter clutch 60 and when the pawl 56 is lifted out ofengagement with a lobe on the primary, the spring 66 tightens to causerotation of shaft 36. The complementary pawl 68 serves merely to preventa back lash of the secondary member 64 and thereby insures the releaseof the spring 66 when the pawls are in the posi tion Shown in Fig. 3.After the filter pawl 56 is raised out of engagement with the lobe onthe primary 58, filtershaft 36.will rotate until the pawl 56 engages thethat filter pawl 56 is always back into engagement with the lobe of thespring clutch in time to guarantee a single one-third of a revolution.

Continuing with the operation of the filter shaft 36, it can beappreciated that as soon as the filter pawl 56 drops into the path ofone of the lobes of the primary 58, that the motion ofthe primary willbe interrupted thereby unwinding the spring 66. If 'it were not for thecomplementary pawl 68, however, the spring would" cyclically grab andrelease to provide a chattering action. The complementary pawl 68 ispivotally supported and spring biased into engaging position.

With this description it can be appreciated that a key stroke or a cycleis determined by a third of the revolu tion of the filter shaft 36. Toreiterate, the rocking of the key lever 16 acts on the interposer totrip a spring clutch to cause a one-third revolution of the filter shaft36, which in turn drives the interposer to the left thereby rockingpredetermined selecting bails 44 to move the corresponding selectinglinks 48. The selecting links 48,

during the one-third revolution of the filter shaft, select thecharacter on the print head 8 which is to be printed on the sheetcarried by the paper feed unit 6.

It follows that two operations which are distinct one from the other arenecessary: (1) it is necessary to select the character and (2) it isnecessary to print the selected character.

Selecting mechanism As shown in Fig. 3, there are seven selecting links48 which can be moved in response to the rocking of the selector bails44. One of the links 48-1 is conditioned for operation for each keylever, and its function is to trigger a selecting clutch, while theother six links 48-2; 48-4; 48-6; 48-8; 48-10; 48-12 are used tocondition dog clutches which in turn, determine the result which isproduced by the selecting clutch under control of the link 48-1.

Reference is now made to Fig. 413, wherein a selector belt 72 is showncontinuously driven under control of a motor (not shown) to rotate aprimary selector shaft driving shaft 74 in a counterclockwise direction.The primary selector shaft is connected to a secondary selector shaftthrough a selecting clutch 76. Actually, the link 48-1 rocks the cyclebell crank 78 which is pivotally supported about a pin 80 carried by theframe. As the nose 82 of hell crank 78 is lifted out of engagement withthe selecting clutch 76, the latter is actuated to drive the secondaryselecting shaft 84 shown in Fig. 4A. The selecting clutch 76 is aconventional spring clutch of a type well known in the art. That is, assoon as the finger 82 is lifted out of engagement with the lobe 83, aspring within thc spring" clutch will grip the primary selecting shaft74 until the finger 82 again engages the lobe 83 to release the springclutch. Selecting clutch 76 is a one revolution clutch, therefore onlyone lobe 83 is provided. The secondary shaft 84 carries a number of dogclutches which are triggered by the selecting links 48, and the dogclutches are conditioned for operation before the selecting clutch 76 isreleased to make a revolution.

In this respect, dog clutches 862, 86-4, 86-6, 86-8, 86-10 and 86-12,respectively, are provided to be operable in response to the movement ofa corresponding selecting link 48. Since the operation of all the dogclutches are identical only one will be described.

Referring to Fig. 4A, each dog clutch 86 comprises a cam 88, an engagingdog 90 and a spring 92 tending to bias the dog 90 into engagement with aslot or key way 94 which runs along the secondary selecting shaft 84.The dog 90 is pivotally-supported on a pin 96 carried by the cam 88 forrocking movement into and out of engagement with the key Way of thesecondary selecting shaft. In the disengaged position, as shown in Fig.4A, a nose of the unlatching pawl 98 is hooked behind the tail of thedog 90 to rock the latter clockwise about its pivot pin 96 therebydisengaging the dog from the key Way. If the unlatching pawl 98 isrocked clockwise about its pivot fulcrum 100, then the dog 90 isreleased, and under control of the spring 92, is pulled into engagementwith the slot 94 of the secondary selector shaft 84 whereby as thelatter is driven through a revolution, the cam 88 is also driven throughone revolution.

In order to unlatch the dogs 90 from engagement with the slot 94 afterthe revolution is completed, the unlatching .pawls 98 are spring biasedinto engagement with the tailsof their corresponding dogs 90. Therefore,as soon as an interposer 22 is disengaged from the filter shaft 36, theunlatching pawl 98 snaps back into the position shown in Fig. 4A. Thesequence of operation, therefore, is that unlatching pawl 98 is firstrocked clockwise about the fulcrum 100; the tail of the dog 96 passescounterclockwise under the unlatching pawl 98 and drops into engagementwith the slot 94 whereupon, as the cam 88 is driven through a revolutionby the secondary selector shaft 84, the unlatching pawl 98 will be backin the position shown in Fig. 4A to grab the tail of the dog 90 andunlatch it by disengaging it from slot 94. Since the dog clutches shouldbe engaged before the secondary shaft 84 starts to rotate, link 481 isconnected to bell crank 78 via a link adjustment that permits theselected dog clutches to be tripped before nose 82 is released from lobe83.

It has been mentioned that a spring 92 is used to drive the dog intoengagement with the slot 94 in the secondary selector shaft. It can beappreciated therefore, that unlessthe cam 88 is blocked from moving, thecombined action of spring 92 and unlatching pawl 98 will act to rotatethe cam 88 clockwise and then dog 90 would not be in position to engagethe slot of the secondary selector shaft at the next cycle of operation.Accordingly, a cornplementary latching pawl 102 is provided for eachofthe dog clutches to prevent rotation of the cam 88 while the dog 90 isunlatched. That is, the cam 88 is provided with a lug 104 and theinterengagement of the lug 104 and latching pawl 102 will preventclockwise rotation (as view in Fig. 4A), but will permitcounterclockwise rotation of cam 88. Hence, toward the end of a completecycle of rotation of cam 88, the lug 104 will act on the nose of thelatching pawl 102 to raise it momentarily against the bias of a spring(not shown). Then as lug 104 passes under latchingv pawl 102, the latterwill snap back to Fig. 4A position. It is this interaction of parts andone c'ycleclutch. At each operation of the key lever somecombination ofthe dog clutches are engaged under the control of their respectiveinterposers and links 48.

which blocks the clockwise rotation of the cam thereby After the dogclutches have been engaged, then the pri mary selector shaft drives theselecting clutch 76 throughone cycle of operation thereby driving thesecondary selector shaft and the engaged cams through one cycle ofrotation. This latter action is designed to produce a selecting cyclewhich will now be described.

A cam follower arm 106, which is pivotally supported about either theupper pivot 108 or the lower pivot 110 (depending on its location), isprovided for each cam 88, respectively. The rocking of a cam followerarm in re sponse to the rotation of its corresponding cam causes" arespective wire pulley 112 (carried by cam follower arm 106) to beraised orlowered (depending on its-location")- thereby rocking the camfollower arm clockwise or counterclockwise about its pivot 108 or 110respectively.- More specifically, the cam follower arm is provided with"a cam follower 107 which is supported for rotation about a pivot 109 andthe cam follower rides on one of thecams 88 driven by the secondaryselector shaft. This rocking of the cam follower arms extends orcontracts the efiective length of a selecting wire 114, Fig. 4C,- whichhas a path around the wire pulleys 112.

With reference to Figs. 4C and 4D of the drawings, the carrier 10 isillustrated schematically as being movable across a printing pagebetween the'left and righthand margins. A carrier loop wire 116 isillustrated as passing around pulleys 118 and 120 to be attached at oneend 122 to the carrier 10 and at the other end 124 to a pulley 126 towhich there is attached the printing head 8. In this arrangement, pulley118 is fixed but free to rotate while pulley 120 is simultaneouslyrotatable and movabletoward and away from pulley 118. If the pulleys118- and 120 remain in the positions illustrated in Fig. 4C, the carrier10 can be moved betweenthe left and right hand margins of the page,without any movement of the pulley 120. If, while the carrier isstationary, a move-- ment is superimposed on the pulley 120, then thelength of the carrier loop 116 will be either increased or dedecreased,and this change in length in the carrier loop 116 rotates the pulley 126and thereby rotates the printing head 8 as later described. The pulley126 is spring" biased in a counterclockwise direction whereupon for eachmovement of the pulley 120 away from pulley 118, the spring will rotatepulley 126 counterclockwise; while movement of pulley 120 toward pulley118 will rotate pulley 126 clockwise in opposition to the spring.

In this arrangement, it can be appreciated that the change in length ofthe selecting wire controls the rotation of pulley 126, and as laterdescribed, the position of the type head 8. With this analogy, it can beappreciated that any change in length of the selecting wire 114' ascontrolled by the movement of the wire pulleys 111 can be used to varythe position of a printing head. In this respect it should be mentionedthat in a half of a spherical type element (as described in copendingU.S. application, Serial No. 547,481, filed November 17,, 1955),

there are eleven rows of lower case characters; and in the-- pulleys112, the type head can be rotated (in lower case) counterclockwise fromhome position one to five columns; or clockwise one to five columns.Then for upper case the type head is rotated first through to positionthe upper case home position in print position before the selectivecolumn movement is super imposed. 1 1

